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| | ==Structure of GS-TnrA complex== | | ==Structure of GS-TnrA complex== |
| - | <StructureSection load='4s0r' size='340' side='right' caption='[[4s0r]], [[Resolution|resolution]] 3.50Å' scene=''> | + | <StructureSection load='4s0r' size='340' side='right'caption='[[4s0r]], [[Resolution|resolution]] 3.50Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4s0r]] is a 28 chain structure with sequence from [http://en.wikipedia.org/wiki/Bacsu Bacsu]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4S0R OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4S0R FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4s0r]] is a 28 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacillus_subtilis_subsp._subtilis_str._168 Bacillus subtilis subsp. subtilis str. 168]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4S0R OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4S0R FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GLN:GLUTAMINE'>GLN</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GLN:GLUTAMINE'>GLN</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">glnA, BSU17460 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=224308 BACSU])</td></tr>
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4s0r FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4s0r OCA], [https://pdbe.org/4s0r PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4s0r RCSB], [https://www.ebi.ac.uk/pdbsum/4s0r PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4s0r ProSAT]</span></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Glutamate--ammonia_ligase Glutamate--ammonia ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.1.2 6.3.1.2] </span></td></tr>
| + | |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4s0r FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4s0r OCA], [http://pdbe.org/4s0r PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4s0r RCSB], [http://www.ebi.ac.uk/pdbsum/4s0r PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4s0r ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/GLN1A_BACSU GLN1A_BACSU] Glutamine synthetase (GS) is an unusual multitasking protein that functions as an enzyme, a transcription coregulator, and a chaperone in ammonium assimilation and in the regulation of genes involved in nitrogen metabolism (PubMed:25691471). It catalyzes the ATP-dependent biosynthesis of glutamine from glutamate and ammonia (PubMed:24158439). Feedback-inhibited GlnA interacts with and regulates the activity of the transcriptional regulator TnrA (PubMed:11719184, PubMed:12139611). During nitrogen limitation, TnrA is in its DNA-binding active state and turns on the transcription of genes required for nitrogen assimilation (PubMed:11719184, PubMed:12139611, PubMed:25691471). Under conditions of nitrogen excess, feedback-inhibited GlnA forms a stable complex with TnrA, which inhibits its DNA-binding activity (PubMed:11719184, PubMed:12139611, PubMed:25691471). In contrast, feedback-inhibited GlnA acts as a chaperone to stabilize the DNA-binding activity of GlnR, which represses the transcription of nitrogen assimilation genes (PubMed:25691471).<ref>PMID:11719184</ref> <ref>PMID:12139611</ref> <ref>PMID:24158439</ref> <ref>PMID:25691471</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </div> | | </div> |
| | <div class="pdbe-citations 4s0r" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 4s0r" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Glutamine synthetase 3D structures|Glutamine synthetase 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacsu]] | + | [[Category: Bacillus subtilis subsp. subtilis str. 168]] |
| - | [[Category: Glutamate--ammonia ligase]] | + | [[Category: Large Structures]] |
| - | [[Category: Chinnam, N G]] | + | [[Category: Chinnam NG]] |
| - | [[Category: Cuthbert, B]] | + | [[Category: Cuthbert B]] |
| - | [[Category: Schumacher, M A]] | + | [[Category: Schumacher MA]] |
| - | [[Category: Tonthat, N K]] | + | [[Category: Tonthat NK]] |
| - | [[Category: Chaperone]]
| + | |
| - | [[Category: Glutamine synthesis]]
| + | |
| - | [[Category: Ligase]]
| + | |
| - | [[Category: Transcription regulation]]
| + | |
| Structural highlights
Function
GLN1A_BACSU Glutamine synthetase (GS) is an unusual multitasking protein that functions as an enzyme, a transcription coregulator, and a chaperone in ammonium assimilation and in the regulation of genes involved in nitrogen metabolism (PubMed:25691471). It catalyzes the ATP-dependent biosynthesis of glutamine from glutamate and ammonia (PubMed:24158439). Feedback-inhibited GlnA interacts with and regulates the activity of the transcriptional regulator TnrA (PubMed:11719184, PubMed:12139611). During nitrogen limitation, TnrA is in its DNA-binding active state and turns on the transcription of genes required for nitrogen assimilation (PubMed:11719184, PubMed:12139611, PubMed:25691471). Under conditions of nitrogen excess, feedback-inhibited GlnA forms a stable complex with TnrA, which inhibits its DNA-binding activity (PubMed:11719184, PubMed:12139611, PubMed:25691471). In contrast, feedback-inhibited GlnA acts as a chaperone to stabilize the DNA-binding activity of GlnR, which represses the transcription of nitrogen assimilation genes (PubMed:25691471).[1] [2] [3] [4]
Publication Abstract from PubMed
All cells must sense and adapt to changing nutrient availability. However, detailed molecular mechanisms coordinating such regulatory pathways remain poorly understood. In Bacillus subtilis, nitrogen homeostasis is controlled by a unique circuitry composed of the regulator TnrA, which is deactivated by feedback-inhibited glutamine synthetase (GS) during nitrogen excess and stabilized by GlnK upon nitrogen depletion, and the repressor GlnR. Here we describe a complete molecular dissection of this network. TnrA and GlnR, the global nitrogen homeostatic transcription regulators, are revealed as founders of a new structural family of dimeric DNA-binding proteins with C-terminal, flexible, effector-binding sensors that modulate their dimerization. Remarkably, the TnrA sensor domains insert into GS intersubunit catalytic pores, destabilizing the TnrA dimer and causing an unprecedented GS dodecamer-to-tetradecamer conversion, which concomitantly deactivates GS. In contrast, each subunit of the GlnK trimer "templates" active TnrA dimers. Unlike TnrA, GlnR sensors mediate an autoinhibitory dimer-destabilizing interaction alleviated by GS, which acts as a GlnR chaperone. Thus, these studies unveil heretofore unseen mechanisms by which inducible sensor domains drive metabolic reprograming in the model Gram-positive bacterium B. subtilis.
Structures of regulatory machinery reveal novel molecular mechanisms controlling B. subtilis nitrogen homeostasis.,Schumacher MA, Chinnam NB, Cuthbert B, Tonthat NK, Whitfill T Genes Dev. 2015 Feb 15;29(4):451-64. doi: 10.1101/gad.254714.114. PMID:25691471[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Wray LV Jr, Zalieckas JM, Fisher SH. Bacillus subtilis glutamine synthetase controls gene expression through a protein-protein interaction with transcription factor TnrA. Cell. 2001 Nov 16;107(4):427-35. PMID:11719184
- ↑ Fisher SH, Brandenburg JL, Wray LV Jr. Mutations in Bacillus subtilis glutamine synthetase that block its interaction with transcription factor TnrA. Mol Microbiol. 2002 Aug;45(3):627-35. doi: 10.1046/j.1365-2958.2002.03054.x. PMID:12139611 doi:http://dx.doi.org/10.1046/j.1365-2958.2002.03054.x
- ↑ Murray DS, Chinnam N, Tonthat NK, Whitfill T, Wray LV, Fisher SH, Schumacher MA. Structures of the B. subtilis glutamine synthetase dodecamer reveal large intersubunit catalytic conformational changes linked to a unique feedback inhibition mechanism. J Biol Chem. 2013 Oct 24. PMID:24158439 doi:http://dx.doi.org/10.1074/jbc.M113.519496
- ↑ Schumacher MA, Chinnam NB, Cuthbert B, Tonthat NK, Whitfill T. Structures of regulatory machinery reveal novel molecular mechanisms controlling B. subtilis nitrogen homeostasis. Genes Dev. 2015 Feb 15;29(4):451-64. doi: 10.1101/gad.254714.114. PMID:25691471 doi:http://dx.doi.org/10.1101/gad.254714.114
- ↑ Schumacher MA, Chinnam NB, Cuthbert B, Tonthat NK, Whitfill T. Structures of regulatory machinery reveal novel molecular mechanisms controlling B. subtilis nitrogen homeostasis. Genes Dev. 2015 Feb 15;29(4):451-64. doi: 10.1101/gad.254714.114. PMID:25691471 doi:http://dx.doi.org/10.1101/gad.254714.114
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